Aim. To evaluate the quality of Public Health Masters' theses sustained by master candidates from a School of Medicine in Lima, Peru. Materials and methods. We reviewed 47 theses which met the inclusion criteria. Theses came from masters programs and focused on public health issues. All the theses were obtained from the medical school library. Scale categories for quality evaluation ranged from excellent to acceptable, and unacceptable. Additionally, we used another scale to evaluate social relevance was based on the number of beneficiaries. The study was conducted in the second half of 2008. Results. A total of 11 (23%) were excellent, 5 (11%) were acceptable, and 31 (66%) were not acceptable. From the 11 excellent theses, four were form the Master of Epidemiology Program, and four were from the Master in Reproductive Health. From the 31 unacceptable theses, most of them (23%) were from the Master of Healthcare Management Program. Conclusion. Around a third of master theses with public health subjects from the Post-Graduate Unit in the School of Medicine are excellent or acceptable regarding the quality of their methods, and a minority were socially irrelevant. © 2011 Educación Médica.